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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>object.keys</title>
</head>
<body>
    

    <script>

        // -> 返回的是一个私有属性的数组
        let obj = {name: 'js',fullname: 'javascript'};

        console.log(Object.keys(obj));

        let ary = [1,2,3,4,5,6];

        console.log(Object.keys(ary));
    
        var arr = ['a', 'b', 'c'];

        console.log(Object.keys(arr));




    </script>
</body>
</html>